Control and trip means for infeed gripper mechanism



1966 M. van SINGH 3,263,991

CONTROL AND TRIP MEANS FOR INFEED GRIPPER MECHANISM Filed April 24, 1964 5 Sheets-Sheet 1 FIG.

INVENTOR.

MAHENDRA VIR SINGH Aamzwem M. VlR SINGH Aug. 2, 1966 CONTROL AND TRIP MEANS FOR INFEED GRIPPER MECHANISM Filed April 24, 1964 5 Sheets-Sheet 2 FBGE INVENTOR.

MAHENDRA VIR SINGH 2, 1966 M. VIR SINGH 3,263,991

CONTROL AND TRIP MEANS FOR INFEED GRIPPER MECHANISM Filed April 24, 1964 5 Sheets-Sheet 3 FIG.4

INVENTOR.

MAHENDRA VIR SINGH Iii/s 1966 M. VlR SINGH 3,263,991

CONTROL AND TRIP MEANS FOR INFEED GRIPPER MECHANISM Filed April 24, 1964 5 Sheets-Sheet 5 59 53 63 64 4a 63 so so en 62 FIG.'?

INVENTOR.

MAHENDRA VIR smen BY United States Patent 3,263,991 CONTROL AND TRIP MEANS FOR INFEED GRIPPER MECHANISM Mahendra Vir Singh, Chicago, Ill., assignor to Miehle- Goss-Dexter, Incorporated, Chicago, 11]., a corporation of Delaware Filed Apr. 24, 1964, Ser. No. 362,446 9 Claims. (Cl. 27151) The invention relates to mechanisms for feeding sheets to a printing press or like machine and has reference more particularly to oscillating infeed gripper mechanism having oscillating cams for controlling the motion of the gripper pads and gripper fingers.

An object of the invention is to provide infeed gripper mechanism for transferring sheets from a position of rest on a feed table to the grippers of a continuously rotating impression cylinder and wherein a conjugate cam system is employed for oscillating the mechanism in combination with control cams which are independently oscillated for producing the required motion of the grippper pads and fingers for each oscillating cycle.

Another and more specific object of the invention resides in the provision of infeed gripper mechanism having conjugate cams for oscillating the mechanism and having oscillating drive gear segments for controlling the motion of separate control cams for producing the opening and closing of the gripper fingers with respect to the gripper pads and for also producing the retracting motion of said fingers and pads in the return stroke of their oscillating cycle.

Another object of the invention is to provide sheet infeed gripper mechanism of the character described which will additionally incorporate novel and improved means for tripping the drive gear segments to prevent oscillation of the control cams in the event a sheet is not presented to the sheet detecting means at the register end of the feed table or in the event a sheet is presented in a misaligned or in an improper registered manner.

Another object of the invention consists in providing sheet gripper structure which is so supported from a gripper supporting shaft as to provide for oscillating movement of the structure, wherein a conjugate cam system is employed for oscillating the sheet gripper structure and wherein control cams are mounted on the supporting shaft for independent rotation, the control cams being oscillated by gear segments so that the cams are caused to control the action of the gripper fingers and the gripper pads.

With these and various other objects in view the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts:

FIGURE 1 is an end elevational view of oscillating infeed gripper mechanism applied to a printing press and which shows the oscillating drive for the gripper mechanism in the form of conjugate cams and also shows the oscillating gear segment for driving the control cams;

FIGURE 2 is an enlarged fragmentary view showing the infeed gripper mechanism in the position the parts assume following the transfer of a sheet to the grippers of the impression cylinder of the printing press;

FIGURE 3 is an enlarged fragmentary view similar to FIGURE 2 but showing the infeed grippers retracted at the end of their feed stroke and the control cam drive gear segment tripped to prevent its oscillation;

FIGURE 4 is a view on the same scale as FIGURE 3 and which shows the position of the gripper fingers and 3,263,991 Patented August 2, 1966 pads of the infeed gripper mechanism as they return to take a registered sheet from the feed table of the press;

FIGURE 5 is a view on the same scale as FIGURE 4, but showing how the grippers and pads remain retracted above the feed table when the drive is tripped;

FIGURE 6 is a fragmentary view, with parts being shown in section, taken substantially on the line 66 of FIGURE 1;

FIGURE 7 is a sectional view taken substantially on line 77 of FIGURE 1 and which shows the structural features of the grippper shaft and the manner in which the gripper fingers and pads are carried thereby;

FIGURE 8 is a side elevational view illustrating the mechanism for tripping the gear segment to prevent its operation when a sheet is not presented to the sheet registering and detecting means; and

FIGURE 9 is a fragmentary view showing one conventional form of sheet detecting means suitable for use with the present invention.

In FIGURE 1 the numeral 10 represents an impression cylinder of a printing press, the cylinder having associated with it in the conventional manner a plate cylinder and a blanket cylinder which, however, are not shown. The sheets to be printed are supported by a registering table 12 and the oscillating sheet infeed mechanism generally designated by numeral 13 is operative for transferring a sheet from the table 12 to the gripper structure 14 carried by the impression cylinder, FIGURE 2. The con jugate cams 15 and 16 are rotated on the axis 17 in timed relation with the impression cylinder, and the rollers 20 and 21 contact the cams, respectively, to oscillate the arms 22 and 23 of the bell crank lever 24 which is pivoted for rocking movement at 25. By means of the link 27 and the arm 28 the oscillating movement of the bell crank 24 is imparted to the infeed gripper mechanism 13. The link 27 is pivotally connected at 30 to the bell crank lever 24 and at 31 to the arm 28. Said arm is, in turn fixed to the reduced end 32, FIGURE 6, of the gripper supporting shaft 34 by means of a hub portion formed integral with the arm and by means of the part 26 and the securing screw 29.

As shown in said figure the gripper supporting shaft 34 extends between the side frames 35 and 36 of the printing press and includes a cylinder portion 37 centrally of the shaft and which provides the brackets 38 and 40 at respective ends. Adjacent bracket 33 the shaft includes the reduced end portions 41 and 42, with portion 42 receiving the ball bearing race 43 and which is located in the side frame 35. The shaft 34 adjacent the bracket 40 is reduced in diameter at 44 and also at 45 from which portion the previously referred to part 32 extends. The portion 45 receives the roller bearing race 46 having location in side frame 36. Thus oscillating movement of the gripper supporting shaft is conveniently effected by a conjugate system of cams and by means of the spaced brackets 38 and 40, forming part of the gripper supporting shaft, the infeed gripper mechanism 13 is supported and oscillated. This structure will now be described.

The gripper shaft 48 of the present mechanism is shown in FIGURE 7, the same extending through brackets 38 and 40 at its respective ends and having a central bore formed therein and which extends longitudinally. At each end of shaft 48 beyond the brackets, the shaft has fixed thereto a roller supporting lever 50, a lever being suitably fixed to each projecting end by means of a split hub portion and which is tightened on the shaft 48 by a tightening of the securing screws 51. At the outer end of each lever 50 a roller such as 52 is suitably mounted for free rotation by the stud shaft 53. The fingers 54 of the gripper mechanism are fixed to the shaft 48 at spaced intervals by the fastening parts 55 which encircle the shaft. Whereas the roller support levers 50 are located beyond the brackets the roller support levers 56 are located within the brackets and each lever carries a roller 57 which is freely rotatable, being mounted on a stud shaft 58. The levers are mounted on the shaft 48 for oscillation independently of the shaft, and for this purpose the flanged adapters 59 are provided. Also, the levers 56 are recessed for accommodating the pad bar 60. The said bar carries the gripper pads 61 and the bar is secured to the levers 56 by the securing screws 62.

For maintaining the rollers 52 and 57 in contact with the control cams to be presently described, the gripper shaft 48 incorporates torsion means in the form of the torsion bars 63. Said bars are located within the bore which extends longitudinally of the shaft 48 and the ends of each bar are formed with the spline teeth 64 and 65, respectively. At the inner end of each torsion bar the spline teeth 64 are fixed to the shaft 48 and at each outer end beyond the split hub portion of each lever 50 the spline teeth 65 are respectively connected to levers 66 which project in the direction of the rollers 57 and have connection with the stud shafts 58. If the torsion bar has been properly preloaded, the rollers 52 will be resiliently held in contact with the gripper finger control cams 68, FIGURES 2 to 5, inclusive, and rollers 57 will be likewise resiliently held in contact with the gripper pad control cams 78. A unitary element comprising a gripper finger control cam 68, a gripper pad control cam 70., and an oscillating drive gear '71 is mounted on the reduced portion 41 of the supporting shaft 34 and a similar unit also comprising a gripper finger control cam 68, a gripper pad control cam 78 and an oscillating drive gear 71 is mounted on the reduced portion 44. The units have oscillating movement on the reduced portions independently of the supporting shaft.

It will be understood from the foregoing that the gripper mechanism 13 will be bodily oscillated by the action of the arm 28 and simultaneously with this movement the invention contemplates that the control cams will be oscillated by gear segments 72 each having teeth 79 which mesh with the teeth on a drive gear 71. The structure for oscillating the gear segments is shown in FIG- URE 6 wherein the impression cylinder is shown as journalled by the trunnions 73 and 74 in the side frames 35 and 36 of the press. The trunnion 74 projects through side frame 36, and the drive gear 75 for driving the impression cylinder is suitably fixed to this part of the same. Said trunnion also provides the cam 76 located between the side frame 36 and the driving gear 75.

The oscillating drive shaft 77 extends between the side frames of the press, being journalled at respective ends by the ball bearing recess 78, and at the right hand end it will be seen that the drive shaft 77 projects beyond the side frame 36 to receive the arm 80 which carries the roller 81 having contact with the cam 76. For maintaining the roller 81 in contact with the cam 76, a torsion bar 82 is provided, the bar extending longitudinally within the shaft 77. The bar is fixed by the spline end 83 to the frame 35 at the left hand end of the shaft, and at the right hand end the torsion bar is suitably fixed by the spline 84 to the shaft. Said shaft adjacent each side frame is reduced in diameter for receiving the gear segments 72, respectively, and which are suitably fixed to the shaft so as to oscillate therewith.

In FIGURE 1 the infeed gripper mechanism 13 is shown in the position of having received a sheet from the feed table 12 and which is gripped between the gripper pads 61 and the gripper fingers 54. With the conjugate cams and 16 rotating in a counterclockwise direction, the gripper mechanism will be oscillated bodily in a direction towards the impression cylinder 18. The control cams 68 and 78 also move in a counterclockwise direction as the roller 81 moves to the low part of cam 76 and the grippers 54 and pads 61 maintain positive control of the sheet. When the gripper mechanism reaches a position approximately midway of its travel in this direction, FIGURE 2, in which position the leading edge of the sheet will be tangent to the said cylinder, the roller 81 will begin moving to the high part of cam 76 and the resultant motion of gear segment-s 72 will cause the control cams to reverse their direction of travel and move in a clockwise direction. The gripper finger control roller will thus move to the low part of cam 68 and the fingers 54 will be opened relative to the pads 61 to release the sheet to the gripper structure 14 of the impression cylinder. The opening of the gripper fingers is accomplished very quickly due to the fact that the gripper mechanism 13 is at this time still moving in a counterclockwise direction. Following transfer of the sheet to the impression cylinder, the gripper mechanism will continue in its travel in a counterclockwise direction until it reaches the end of its feed stroke in this direction, whereupon the gripper pads and the gripper fingers are both retracted to the position as illustrated in FIGURE 3. At this point the control cams 68 and 70 have reached the end of their motion in a clockwise direction with the gripper finger control roller riding on the high part of cam 68 and the pad control roller riding on the low portion of cam 70. Due to the contour of cam 76 the control cams 68 and 78 remain in the position of FIGURE 3 for a substantial portion of the feed cycle and thus during the initial portion of their return stroke the gripper pads and fingers remain retracted. However, as the grippers and pads approach the feed table, the control cams start to move in a counterclockwise direction thereby causing the pads and fingers to be projected as shown in FIGURE 4 as they return to engage the next registered sheet on the feed table. The position of the parts prior to gripping a sheet is shown in FIGURE 4 wherein it will be observed that the gripper pads 61 are located above the table, whereas the gripper fingers 54 are projected below the table. In this figure the gripper mechanism is still moving in a clockwise direction, whereas the control cams have commenced to move in a counterclockwise direction. Continued counterclockwise motion of the control cams will cause the pads and fingers to close on the registered sheet, as shown in FIGURE 1, whereupon the cycle is repeated.

In the event a sheet is not presented to the sheet detecting means at the feed table, or in the event the sheet is presented but is not properly registered, the invention provides means for stopping the motion of the gear segments 72 to thereby prevent oscillation of the cams 68 and 70. As a result, the gripper pads and gripper fingers are held in a retracted position. Although the gripper mechanism 13 continues to oscillate toward the feed table, the grippers and pads remain in their retracted position wherein they are inoperative to grip a sheet on the table. This is clearly evident from FIGURE 5 wherein it will be seen that when the gear segments 72 are stopped, the cams 68 and 70 are held stationary in the position which they reach at the end of their clockwise stroke. Consequently, as the gripper mechanism oscillates the roller 52 will remain on the high part of cam 68 and the roller 57 rides on the low part of cam 70 so that the gripper fingers 54 and pads 61 remain retracted. In the retracted position as shown in said figure the gripper pads and also the gripper fingers are located above the feed table.

In FIGURE 8 the oscillating gear segments are illustrated as having a flange 85 fixed to and projecting from the lower forward edge of each segment. The flange forms a latch with respect to a latching lever 86 pivoted at 87 and actuated by the rod 88. In FIGURE 8 the gear segments 72 are shown as held against movement in a clockwise direction by the latching lever 86 since said lever has been actuated into its dotted line position. Although cam 76 continues to rotate it is not effective for oscillating the gear segments as celarly evident from FIGURE 5.

The sheet detaching means, FIGURE 9, may comprise pivot members 90 pivoted at 91 and adapted to have pendulum-like movement with respect to said pivot. The pivot members are located at the front edge of the feed table, being spaced along said edge. When the members are engaged by a sheet they are caused to assume the full line position as shown in FIGURE 9, in which position the lower edge of the pivot members will miss the latching trough 92 when said members are moved in a down direction. However, if a sheet is not presented to the detecting members, or if a sheet is improper-1y registered, then one or more of the members will remain in the dotted line position of FIGURE 9 in which position the trough 92 will act as a latch preventing the detecting members from moving fully in a down direction. The said members are bodily movable in an up and down substantially vertical direction since the rod 93 is pivoted at 94 and the same joins with rod 95 at the pivot connection 91 for the members. The rod 93 carries roller 96, having contact with the rotating cam 97. Accordingly, as the cam rotates the rod 93 is oscillated and thus the desired up and down motion is given to the detecting members.

The movement of rod 95 is communicated to the lever 98 having a fixed pivot 100 and which, in turn is pivotally connected to the link 101 by the connecting rod 102. The link 101 is pivoted to a lever 103 which is mounted for rocking movement at 104. The upper end of lever 103 is adapted to engage the stop 105 and the lever is yieldingly held against the stop by the coil spring device 106. An arm 107 is also pivotally mounted on axis 104 and the same carries the roller 108 which contacts the rotating cam 110. The coil spring tensioning device 111 is effective in maintaining the roller 108 in contact with the cam 110 and as the cam rotates the arm 107 is oscillated.

The latch end 112 of arm 107 will normally remaindisconnected from the link 101. At least this is the case except when the link 101 remains in a down posi tion, thereby causing the latch 112 to contact the shoulder formed in the link, and when this latching engagement takes place the oscillating motion of arm 107 in 'a counter-clockwise direction is imparted to lever 103.

The lever 103 is provided with a bottom extension 113, the extension thus having limited movement to and from the full and dotted line positions as shown in FIGURE 8. In the full line position the extension will engage the latch arm 114 provided by a member rotatable on shaft 115 and having three additional arms, namely 116, 117 and 118. The arm 117 is adapted to contact the stop 120 when the four-arm member is released, since the spring tensioning device 121 connecting with arm 116 at 122 is effective to move the four-arm member in this direction. The arm 118 is pivotally joined at 123 to the rod 88 which as previously described is connected at its opposite end to the latch lever 86.

As long as properly registered sheets on the feed table 12 are presented to the pivoted sheet detecting members 90, they wall pivot to assume the full line position of FIGURE 9, and as arm 93 is moved down, as permitted 'by the rotation of cam 97, the sheet detecting members will move down for the full extent, since the members will miss the latching trough 92. This full downward movement of the sheet detecting members is transmitted by rod 95 to lever 98 and through the connecting rod 102 to the link 101. With full downward movement of the sheet detecting members the link 101 will be fully elevated and thus oscillating movement in a counterclockwise direction of arm 107 caused by rotation of cam 110 is not communicated to the link. The latching extension 113 of lever 103 thus remains in contact with arm 114. The arm 118 of the four-arm member thus remains in position as shown in FIGURE 8, and the latching lever 86 remains in an inoperative position. In said inoperative position of lever 86, the gear segments 72 are free to oscillate in both directions.

In the event a sheet is not presented to the pivoted members 90, or if the sheet is improperly registered, one or more of the pivoted sheet detecting members will remain in the dotted line position of FIGURE 9. Accordingly, when the pivot members are caused to move in a down direction the latch trough 92 will prevent full downward movement and thus through arm 95, lever 98 and the connecting rod 102, the link 101 will be held in a down position. Oscillation movement of arm 107 in a direction towards the left will thereupon be transmitted to link 101 and thus to lever 103 causing the latching extension 113 to move to the right into its dotted line position. This releases the four-arm member which is resiliently biased to cause arm 117 to move into contact with stop 120. This counter-clockwise rotation of the four-arm member will move rod 88 upwardly causing the latching lever 86 to pivot into its dotted line position, in which position the latching lever 86 will engage flange and latch the gear segments 72, preventing oscillating movement thereof in a clockwise direction.

In accordance with the invention the control carns 68 and 70 are mounted on the gripper supporting shaft 34 so as to have rotation independently of the shaft. In fact, during operation of the infeed gripper structure, the gripper supporting shaft will at times be rotating in one direction, whereas the control cams will be rota-ting in a reverse direction. The net result of the oscillating rotating of the control cams and the bodily oscillating movement of the entire gripper structure is employed to cause the gripper fingers and the gripper pads to have the required movements for opening and closing on a sheet at the feed table and for releasing the sheet to the grippers of the impression cylinder. The retracting movement of the fingers and pads is also provided for by the particular cont-our given the control cams, and it will be understood that when the gear segments are tripped and held against movement by the latching lever 86, the gripper fingers and the gripper pads are in a retracted position. The said par-ts remain in this retracted position for the following cycle during which the gripper mechanism is oscillated in a direction toward the feed table.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings as various other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, a gripper shaft adapted to have bodily oscillating movement in an arcuate path between said support and said member, gripper fingers and gripper pads carried by said shaft and mounted thereon for opening and closing movements relative to said support and member, a gripper supporting shaft for supporting said gripper shaft, and means for actuating said gripper fingers and said gripper pads to cause said opening and closing movements thereof, 'said actuating means including respective cams mounted on said gripper supporting shaft for oscillating rotation independently of the gripper supporting shaft.

2. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, a gripper shaft adapted to have bodily oscillating movement in an arcuate path between said support and said member, gripper fingers and gripper pads carried by said shaft and mounted thereon for opening and closing movements relative to said support and member, a gripper supporting shaft providing means for journalling said gripper shaft, means for producing oscillating rotation of the gripper supporting shaft, and other means for actuating said gripper fingers and said gripper pads to cause said opening and closing movements thereof, said other means including respective cams mounted on said gripper supporting shaft for oscillating rotation independently of the gripper supporting shaft.

3. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, a gripper shaft adapted to have bodily oscillating movement in an arcuate path between said support and said member, gripper fingers and gripper pads carried by said shaft and mounted thereon for opening and closing movements relativeto said support and member, a gripper supporting shaft providing means for journalling said gripper shaft, conjugate cam means for producing oscillating rotation-of the gripper supporting shaft, and other means for actuating said gripper fingers and said gripper pads to cause said opening and closing movements thereof, said other means including a control cam for the fingers and a control cam for the pads, said control cams being mounted on the gripper supporting shaft for oscillating rotation independently of the gripper supporting shaft.

4. A sheet transfer device for feeding sheets as defined in claim 3, additionally including an oscillating gear segment for effecting said oscillating rotation of the control cams.

5. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, a gripper shaft adapted to have bodily oscillating movement in an arcuate path between said support and said member, gripper fingers and gripper pads carried by said shaft and mounted thereon for opening and closing movements relative to said support and member, a gripper supporting shaft providing radially extending brackets for journalling said gripper shaft, conjugate cam means for producing oscillating rotation of the gripper supporting shaft, control cams for respectively actuating the gripper fingers and the gripper pads to cause said opening and closing movements thereof, said control cams being mounted on said grippersupporting shaft for oscillating rotation independently of the gripper supporting shaft, a drive shaft adapted to have oscillating rotation, and a gear segment fixed to and oscillated by said drive shaft, said oscillating gear segment effecting the oscillating rotation of the control cams.

6. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, spaced frame members, a gripper supporting shaft journalled by said spaced frame members, a gripper shaft carried by the supporting shaft and adapted to have bodily oscillating movement in. an arcuate path between said support and said continuously rotating member as the gripper supporting shaft is oscillated, gripper fingers and gripper pads carried by said gripper shaft and mounted thereon for opening and closing movements relative to said support and the, said rotating member, conjugate cam means for producing oscillating rotation of the gripper supporting shaft, and other means for actuating said gripper fingers and gripper pads to cause said opening and closing movements thereof, said other means including a control cam for the fingers and a control cam for the pads, said control cams being mounted on the gripper supporting shaft for oscillating rotation independently of the shaft.

7. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, spaced frame members, a gripper supporting shaft journalled by said spaced frame members, a gripper shaft, radially extending brackets provided by said gripper supporting shaft for journalling the gripper shaft, conjugate cam means for producing oscillating rotation of the gripper supporting shaft, whereby the gripper shaft is bodily oscillated in an arcuate path between said support and said continuously rotating member as the gripper supporting shaft is oscillated, griper fingers and gripper pads carried by said gripper shaft and mounted thereon for opening and closing movements relative to the support and the said rotating member, a unitary member mounted on the gripper supporting shaft for rotating independently of the said gripper supporting shaft, said unitary member to thereby cause oscillating rotation of the control cam for the pads and an oscillating drive gear, a drive shaft journalled by the spaced frame members and adapted to have oscillating movement, a gear segment fixed to and oscillated by the drive shaft, said gear segment having meshing relation with the drive gear of said unitary member to thereby cause oscillating rotation of the control cams, and means respectively connecting the gripper fingers with the finger control cam and the gripper pads with control cam for the pads, whereby as the control cams are oscillated the gripper fingers and pads are caused to have said opening and closing movements.

8. In a sheet transfer device for feeding sheets from a support to a continuously rotating'member, in combination, a gripper shaft adapted to have bodily oscillating movement in an arcuate path between said support and said member, gripper fingers and gripper pads carried by said shaft and mounted thereon for opening and closing movements relative to said support and member, a gripper supporting shaft providing means for journalling said gripper shaft, means producing oscillating rotation of the gripper supporting shaft, other means for actuating said gripper fingers and said gripper pads to cause said opening and closing movements thereof, said other means including respective control cams mounted on said gripper supporting shaft for oscillating rotation independently of the gripper supporting shaft, sheet detecting means at said support, and tripping means operative to prevent oscillating movement of the control cams as the gripper shaft moves in a direction towards said support in the event a sheet is not presented to the sheet detecting means or is presented in an improperly registered manner.

9. In a sheet transfer device for feeding sheets from a support to a continuously rotating member, in combination, a gripper shaft adapted to have bodily oscillating -movement in an arcuate path between said support and said member, gripper fingers and gripper pads carried by said shaft and mounted thereon for opening and closing movements relative to said support and member, a gripper supporting shaft providing radially extending brackets for journalling said gripper shaft, conjugate cam means for producing oscillating rotation of the gripper supporting shaft, control cams for respectively actuating the gripper fingers and the gripper pads to cause said opening and closing movement thereof, said control cams being mounted on the gripper supporting shaft for oscillating rotation independently of the gripper supporting shaft, a drive shaft adapted to have oscillating rotation, a gear segment fixed to and oscillated by said drive shaft, said oscillating gear segment effecting the oscillating rotation of the control cams, sheet detecting means at said support, and tripping means for latching the gear segment to prevent oscillating movement of the gear segment and the control cams as the gripper shaft moves in a direction towards the support in the event a sheet is not presented to the sheet detecting means or is presented in an improperly registered manner.

References Cited by the Examiner UNITED STATES PATENTS 317,218 5/1885 Scott 271-82 M. HENSON WOOD, JR., Primary Examiner.

J. N. ERLICH, Assistant Examiner. 

